The canonical correlation analysis
(CCA) forecast of SST in the central Pacific (Barnett et al. 1988, Science, 241,
192-196; Barnston and Ropelewski 1992, J. Climate, 5, 1316-1345), is shown
in Figs. F1 and F2. This forecast
is produced routinely by the Prediction Branch of the Climate Prediction Center. The
predictions from the National Centers for Environmental Prediction (NCEP) coupled
ocean/atmosphere model (Ji et al. 1998, Mon. Wea. Rev, 126, 1022-1034) are
presented in Figs. F3 and F4a, F4b. Predictions from the Markov model (Xue,
Y. et al. 2000: ENSO prediction with Markov model: The impact of sea level. J. Climate,
13, 849-871) are shown in Figs. F5 and F6.
Predictions from the latest version of the LDEO model (Chen,
D. et al. 2000, Geophys. Res. Let., 27,
2585-2587) are shown in Figs. F7 and F8.
Predictions using linear inverse modeling (Penland and Magorian 1993, J. Climate, 6,
1067-1076) are shown in Figs. F9 and F10.
Predictions from the Scripps / Max Planck Institute (MPI) hybrid coupled model (Barnett et
al. 1993, J. Climate, 6, 1545-1566) are shown in Fig. F11. Predictions from the ENSO-CLIPER statistical model
(Knaff, J. A. and C. W. Landsea 1997, Wea. Forecasting, 12, 633-652) are
shown in Fig. F12. Niņo
3.4 predictions are summarized in F13,
which is provided by the Forecasting
and Prediction Research Group of the IRI.
The CPC and the contributors to the Forecast Forum caution potential users of
this predictive information that they can expect only modest skill.
Based on current conditions and recent observed
trends, it is most likely that near average (ENSO-neutral) conditions
will continue in the tropical Pacific through the Northern Hemisphere
Oceanic and atmospheric conditions in the tropical Pacific were near
average (ENSO-neutral) during August 2003. Equatorial ocean surface
temperatures greater than +0.5°C
(~1°F) above average were found
in the region between 150°E and
165°W while temperatures were
below average between 90°W and
the South American coast (Figs. T9, T18). During July and
August very little net change was observed in the SST anomalies in the
Niņo regions (Table T2).
Positive equatorial upper-ocean temperature departures continued to
weaken in the eastern Pacific during August 2003 while positive
departures increased in magnitude in the central equatorial Pacific (Figs.
T15, T17). Overall the basin-wide upper ocean heat content was
slightly greater than average during the month (Fig. T17).
Some atmospheric indices, such as the Tahiti-Darwin SOI, and central
Pacific low-level (850-hPa) zonal wind and OLR, have displayed
considerable month-to-month variability and no consistent trend towards
either La Niņa or El Niņo
over the past few months (Table T1).
The latest statistical and coupled model forecasts indicate
considerable uncertainty for the next several months (Figs. F1,
F4a, F4b, F5, F6, F7,
F8, F9, F10,
F11, F12, F13).
However, a majority of the forecasts indicate near average (ENSO-neutral)
conditions (Niņo 3.4 SST
anomalies between -0.5°C and +0.5°C)
through the NH winter 2003-2004. This is consistent with current
conditions and the lack of any consistent trends in the suite of oceanic
and atmospheric indices.
Weekly updates of SST, 850-hPa wind, OLR and features of the
equatorial subsurface thermal structure are available on the Climate
Prediction Center homepage at: